Role of activated growth factors in lumbar spinal fusions

Background: The concentration of platelets into an activated growth factor (AGF) gel may stimulate graft consolidation into a fusion mass. Preoperative hemodilution and intraoperative clot activation may also reduce the overall blood loss. Consequently, the need for postoperative transfusions may also be reduced. Objective: The objective of this work was to report our experience with AGF platelet gels in transforaminal lumbar interbody fusion (TLIF) procedures. Methods: A consecutive series of patients between 1996 and 1999 undergoing one- and two-level TLIFs with AGF were compared with a consecutive series of TLIF patients who did not receive AGF. Sixty-two control subjects who did not receive AGF and 22 patients who received an AGF platelet gel were compared after 41 and 34 months of follow-up, respectively. Results: On average, the AGF group required 18 minutes of additional preincision anesthesia (P = 0.0001). No statistical differences in the operative times, estimated blood loss, postoperative drainage, percentage of patients requiring a transfusion, or length of hospitalization were appreciated between the two groups. The 19% decrease in the arthrodesis rate of the AGF group, as compared with the control group, did not reach statistical significance. Platelet counts from the AGF platelet concentrates demonstrated an average 3.5-fold increase compared with preoperative serum levels. Conclusions: The theoretical benefits of AGF platelet gel technology were not clinically appreciated. The cost of implementing this technology may therefore outweigh its theoretical benefits.